Cancer is a disease that seriously threatens people’s life and health, and cancer screening is important. However, for different parts of cancer, the screening items may be different. For example, for common cancers of the gastrointestinal tract, such as stomach cancer and intestinal cancer, screening mainly involves endoscopy, such as gastroscopy, colonoscopy or small intestinal microscopy if necessary, and any other imaging tests or imaging tests cannot completely replace gastroscopy. In addition, for cancers of the lung, the main test is chest CT, which can detect the occupying lesions and then confirm the diagnosis by percutaneous lung aspiration biopsy or bronchoscopy. In women, cervical cancer is mainly diagnosed by colposcopic biopsy, but of course, cervical smear and TCT can be done first for routine physical examination. If abnormalities are found, further colposcopic biopsy can be done.